CLEARING THE WAY FOR EMPIRICISM: LOCKE S ATTACK ON NATIVISM To say that a notion is imprinted on the mind, and yet at the same time to say, that the mind is ignorant of it, and never yet took notice of it, is to make this impression nothing. No proposition can be said to be in the mind, which it never yet knew, which it was never yet conscious of. Locke, An Essay Concerning Human Understanding Empiricism has a long and distinguished history. Such influential thinkers as Aristotle, Thomas Aquinas, Thomas Hobbes, Francis Bacon, John Locke, George Berkeley, David Hume, Adam Smith, Thomas Reid, and John Stuart Mill are not only some of its most important advocates, but are generally recognized as those who are the most distinguished in its line of defenders. Yet, among them, no one person arguably stands out as much as John Locke, the so-called father of the modern empiricist program. Of course, that does not imply that his version of empiricism is correct or that contemporary empiricists are committed to the theory he works out. No, to bestow that honor on Locke is really to say two things. Foremost, it is to say that he is the first modernist thinker to make a substantive effort at working out the nature and details of the empirical theory of the mind and its capacities. Second, it is to say that there is no better work with which to try to understand the empiricist research project than his landmark twovolume work entitled An Essay Concerning Human Understanding (hereafter Essay). Empiricism & the extent of human cognitive capacities To begin, let us ask: what is empiricism? As I noted earlier, it is be committed to the idea that there is an empirical constraint on our understanding of the nature of the human mind and its capacities. Let us see if we can say something more substantive that that, however. Let us take it to be the view that EMPIRICISM: Since (i) no human has any mental content whatsoever at the point of birth, then (ii) any acquisition of mental content ultimately depends on having sensory experiences of the relevant type, and mental operations on those sensory states. As we can see, EMPIRICISM tells us that humans are born no mental content such that unless a person has the relevant sensory faculties, e.g., vision, touch, etc., he cannot any mental content. 1 Yet, EMPIRICISM also tells us that having those sensory faculties is not by itself sufficient for having mental content. Not only must a person have the relevant sensory faculties, he must also have had an experience of the relevant thing in question in order to have mental content concerning that thing. This is on account of the fact that EMPIRICISM tells us that, we are born, as Locke famously describes, analogous to a tabula rasa, a blank slate. This is why empiricists take it that all of our mental content ultimately comes from sensory experiences of the relevant type. Each of us has mental content, but since we re born with no mental content, it must ultimately come from sensory experiences of the relevant type. 2 At this juncture, it s important to point out that EMPIRICISM is a psychological thesis, i.e., it tells us about the source of mental content, that is, how we come to have it. While we will have more to say about this as we go, empiricists will also advance it as epistemic thesis, namely, one that tells us about what warrants or justifies our beliefs (and sometimes yields knowledge). So, empiricists will try to provide us with both types of theses. Let us call the former type content empiricism and the latter type epistemic empiricism. 1 Kinds of mental content include concepts, beliefs, knowledge, etc. 2 As we will see, the right side of the conjunct mental operations on those sensory states is required in order to have thoughts (as opposed to mere sensory perceptual states).
One final point. There seems to be a theoretical relation between the two types of empiricisms: one cannot be an epistemic empiricist without also being a content empiricist. Why? Given that a person can have the relevant type of knowledge only if he also has the relevant beliefs and concepts, empiricists tell us that any beliefs and concepts we have must also be acquired via sensory experiences of the relevant types. Even so, that does not, as we will see, imply that knowledge empiricists believe all knowledge is empirical knowledge. Again, we will have more to say about this as we go, but for now, suffice it to say that many even most? empiricists accept that we do have non-empirical knowledge, e.g., that all red things are red, that all bachelors are unmarried, etc. Locke & the motivations for empiricism Locke seeks to motivate empiricism on the basis of two claims. First, he attacks its alternative: nativism. 3 He does this by arguing both that there is no evidence that nativism is true, and worse, that there is evidence that it is false on the grounds that it is incoherent. If he is right, then given that nativism and empiricism are mutually exclusive, empiricism must be true. Second, he argues that empiricism is equally, if not more, capable of explaining all the relevant data with respect to human cognition than nativism and do so with greater ontological parsimony. On nativism Before we consider his attack of nativism, let us first make sure we understand what that theory says. Let us understand it as the theory that NATIVISM: The view that all human beings have mental content at the point of birth. (Famous nativists include Plato, René Descartes, Gottfried Wilhelm Leibniz, and Noam Chomsky.) According to this view, we humans are born with ideas, so-called innate ideas. Of course, the nativist theory as just described does not say a great deal about the exact source of our mental content; but neither does the empiricist account as described earlier. We will address those issues in more detail as we consider each thinker s views on these matters. Varieties of nativism: some important differences The descriptions just given are helpful as a starting point, but we need to take the discussion of these views further; for there are many different types of nativist and empiricism theories. While we ll discuss the various types of empiricism later, let us for now distinguish the different kinds of nativist views. Distinction 1: strong versus weak versions of nativism Strong nativism: the view that all of the mental content we will ever have is present at birth (e.g., Leibniz). Weak nativism: the view that at least some mental content we will have is present at birth (e.g., Descartes, Chomsky). Distinction 2: propositional versus concept versions of nativism Propositional nativism: the view that we are born with mental content that includes propositional information. While propositional nativists disagree as to the exact mental content with humans are 3 Nativism is sometimes called innatism.
born, some common examples claimed are the propositions that all events have a cause, that all bodies are extended, that God exists, that killing for pleasure is morally wrong, etc. Concept nativism: the view that we are born with mental content includes concepts. Again, while concept nativists disagree as to the exact mental content we are born with, some common examples argued for are the concepts of causation, substance, identity, infinity, arithmetical operations, a divine being, moral concepts, etc. Locke s worries with nativism According to Locke, the nativist account of non-empirical ideas faces a number of substantive problems. He attempts to demonstrate this in two steps. In step one, he considers what he calls the nativist s great argument, and argues that while it is formally valid, it is nevertheless formally unsound. In step two, he presents his Dilemma Argument (against nativism). Let us consider each step in turn. On step one: against the nativist s great argument Locke begins his attack of nativism by considering two speculative as opposed to what he calls practical propositions: and PC1: Whatever is, is, PC2: It is not possible that x is F and not-f at the very same moment. He says that, if there are any propositions with which all humans are born, that is, are innate, then PC1 and PC2 must be part of that set. Why? For PC1 and PC2 are two claims that no rational person would reject. Let us call PC1 and PC2, The Paradigm Cases. Locke thinks this noteworthy because he believes that the nativist defends of his view with The Argument from Universal Assent. The Argument from Universal Assent (N1) If p is a principle to which all humans assent, then p is innate. [Premise] (N2) The Paradigm Cases are principles to which all humans assent. [Premise] (N3) The Paradigm Cases are innate. [From N1,N2] According to Locke, both (N1) and (N2) are false. However, he says that even if (N1) is true, (N3) is false given that (N2) is false. Is he correct? A quick detour: Locke s conflation of nativism and rationalism It does not follow from NATIVISM that a person is aware of any mental content with which they are born unless one connects it necessarily with an access theory. All the nativist qua nativist is committed to is the claim that mental content is present at the point of birth, not that we re aware of it. Of course, nativists will likely supplement their theory with such an access theory; for the point of nativism is to help explain how we have and accept certain ideas. Historically, the standard access theory that people who espouse nativism also adopt is rationalism. In order to specify the rationalist theory, let us specify some concepts: a priori versus a posteriori justification, and pure and impure reason. A priori versus a posteriori justification The a priori a posteriori justification distinction is an epistemological distinction regarding two kinds of well-grounded or rationally justified beliefs. Let us state the difference as follows:
A priori justification: Person S is epistemically justified a priori in believing that a proposition p is true only if (i) S has some justifier j for believing that p is true and (ii) S s having j does not require that S be able to appeal to a particular sensory experience e. A posteriori justification: Person S is epistemically justified a posteriori in believing that a proposition p is true only if (i) S has some justifier j for believing that p is true and (ii) S s having j does require that S be able to appeal to a particular sensory experience e. The following are putative examples of propositions that we are epistemically justified a priori to believe: if x>y and y>z, then x>z, that all red things are red, that bachelors are married, etc. Putative examples of propositions that we are epistemically justified a posteriori to believe are that there are more than two people in the room, that at least some apples are red, Jones is a bachelor, etc. It is arguably the case that the former does not require an appeal to a particular sensory experience to be an epistemically justified belief, but that the latter does require such an appeal in order to be an epistemically justified belief. Pure versus impure reason With that in mind, we can now make the pure impure reason distinction. Let us understand the difference as follows: Pure reason: reasoning such that every premise used in the argument is a priori justified. Impure reason: reasoning such that at least one premise used in the argument is a posteriori justified. With these in mind, we can now state the rationalist view as the view that RATIONALISM: Humans can have knowledge about the external world via pure reason. Putative examples include: I exist, corporeal substances are essentially extended, God exists, it s morally wrong to torture Canadians for pleasure, etc. As we can see, RATIONALISM is an epistemic theory; it s a theory that tells us about the acquisition of propositional knowledge. It is this theory that Locke also seems to have in mind as a target and rightly so. For epistemic empiricism takes it that any knowledge of the external world must be (in some way) a posteriori-based. Back to Locke s case. On step two: against the coherence of nativism Locke s Dilemma Argument (against nativism) (1) When nativists claim that an idea i is innate, then they are claiming either (a) that all persons have i naturally imprinted in the mind (though they may or may not be aware/conscious of i) or (b) that all persons have the capacity to have i. [Premise] (2) If the (a) analysis is correct, then nativism is incoherent. [Premise] (3) If the (b) analysis is correct, then nativism is trivially true. [Premise] (4) Nativism is either incoherent or it is trivially true. [From 1-3] As we will see, Locke expects that we will not be bothered by the claim (5) Nativism is not trivially true, from which he ultimately infers that (6) Nativism is incoherent.
Locke s defenses of premises (2) and (3) of his Dilemma Argument In defense of (2): The Transparency of the Mental Thesis Argument (A) If the (a) analysis is correct, then it is possible both that S has an idea in S s mind, but that S is not aware/conscious of i. [Premise] However, as the nativist agrees, it is necessarily true that (B) An idea i is in S s mind only if S is aware/conscious of i. [Premise: The Transparency of the Mental Thesis] Thus, the nativist is committed to the claims that (C) It is possible that both S has an idea in S s mind, but that S is not aware/conscious of i. [From A] and (D) It is impossible that both S has an idea in S s mind, but that S is not aware/conscious of i. [From B] Hence, it follows that (E) If the (a) analysis is correct, then nativism is incoherent. [From A-D] In defense of (3): The Triviality Argument. (F) (G) If the (b) analysis is correct, then an idea i being innate just means that all persons have the capacity to have i. [Premise] If that is what it is for an idea i to be innate, then i being innate idea is compatible with any proposition that individuals know, even those that are acquired empirically! In other words, no one not even empiricists! deny that persons have the capacity for having ideas. [Premise] Accordingly, (H) (I) Thus, (J) If the (b) analysis is correct, then all ideas are innate. [From F-G] If all ideas are innate, then nativism is trivially true. [Premise] If the (b) analysis is correct, then nativism is trivially true. [From H,I] Locke s Tabula Rasa Argument (i) (ii) (iii) (iv) If any proposition is innate, then The Paradigm Cases are innate. [Premise] The Paradigm Cases are not innate. [Premise] No proposition is innate. [From i,ii] There are no propositions that are naturally imprinted in the mind. [From iii] (v) The mind, at birth, is like a tabula rasa (i.e., analogous to a blank sheet of paper). [From iv] 4 4 2019, Richard G. Graziano. All rights reserved. This material may not be used, or duplicated in part or whole without express written permission by the author.