In the Enquiry, we’ve seen Hume use his three main principles (CP, SP, and CPY), and deploy his two main distinctions (impressions vs. ideas; matters of fact vs. relations of ideas). We’ve seen Hume’s application of these principles to the external world, God, and causation/induction. Hume is, rather remarkably, silent on the question of the self. Is the self a substance? If so, is it material, or immaterial? We have to turn to the much earlier Treatise to find out Hume’s views. The appendix gives us some indication of why Hume chose not to discuss the topic of the self in the Enquiry.
I had entertain’d some hopes, that however deficient our theory of the intellectual world might be, it wou’d be free from those contradictions, and absurdities, which seem to attend every explication, that human reason can give of the mate- rial world. But upon a more strict review of the section concerning personal identity, I find myself involv’d in such a labyrinth, that, I must confess, I neither know how to correct my former opinions, nor how to render them consistent. If this be not a good general reason for scepticism, ’tis at least a sufficient one (if I were not already abundantly supplied) for me to entertain a diffidence and modesty in all my decisions. I shall propose the arguments on both sides, beginning with those that induc’d me to deny the strict and proper identity and simplicity of a self or thinking being.
When we talk of self or substance, we must have an idea annex’d to these terms, otherwise they are altogether unin- telligible. Every idea is deriv’d from preceding impressions; and we have no impression of self or substance, as some- thing simple and individual. We have, therefore, no idea of them in that sense.
Whatever is distinct, is distinguishable; and whatever is distinguishable, is separable by the thought or imagination. All perceptions are distinct. They are, therefore, distinguishable, and separable, and may be conceiv’d as separately exis- tent, and may exist separately, without any contradiction or absurdity. When I view this table and that chimney, noth- ing is present to me but particular perceptions, which are of a like nature with all the other perceptions. This is the doctrine of philosophers. But this table, which is present to me, and the chimney, may and do exist separately. This is the doctrine of the vulgar, and implies no contradiction. There is no contradiction, therefore, in extending the same doctrine to all the perceptions.
In general, the following reasoning seems satisfactory. All ideas are borrow’d from preceding perceptions. Our ideas of objects, therefore, are deriv’d from that source. Consequently no proposition can be intelligible or consistent with regard to objects, which is not so with regard to perceptions. But ’tis intelligible and consistent to say, that objects exist distinct and independent, without any common simple substance or subject of inhesion. This proposition, therefore, can never be absurd with regard to perceptions.
When I turn my reflection on myself, I never can perceive this self without some one or more perceptions; nor can I ever perceive any thing but the perceptions. Tis the composition of these, therefore, which forms the self. We can con- ceive a thinking being to have either many or few perceptions. Suppose the mind to be reduc’d even below the life of an oyster. Suppose it to have only one perception, as of thirst or hunger. Consider it in that situation. Do you conceive any thing but merely that perception? Have you any notion of self or substance? If not, the addition of other perceptions can never give you that notion.
The annihilation, which some people suppose to follow upon death, and which entirely destroys this self, is nothing but an extinction of all particular perceptions; love and hatred, pain and pleasure, thought and sensation. These there- fore must be the same with self; since the one cannot survive the other. Is self the same with substance? If it be, how can that question have place, concerning the subsistence of self, under a change of substance? If they be distinct, what is the difference betwixt them? For my part, I have a notion of neither, when conceiv’d distinct from particular perceptions.
Philosophers begin to be reconcil’d to the principle, that we have no idea of external substance, distinct from the ideas of particular qualities. This must pave the way for a like principle with regard to the mind, that we have no notion of it, distinct from the particular perceptions.
So far I seem to be attended with sufficient evidence. But having thus loosen’d all our particular perceptions, when I proceed to explain the principle of connexion, which binds them together, and makes us attribute to them a real sim- plicity and identity; I am sensible, that my account is very defective, and that nothing but the seeming evidence of the precedent reasonings cou’d have induc’d me to receive it. If perceptions are distinct existences, they form a whole only by being connected together. But no connexions among distinct existences are ever discoverable by human understand- ing. We only feel a connexion or determination of the thought, to pass from one object to another. It follows, therefore, that the thought alone finds personal identity, when reflecting on the train of past perceptions, that compose a mind, the ideas of them are felt to be connected together, and naturally introduce each other. However extraordinary this con- clusion may seem, it need not surprize us. Most philosophers seem inclin’d to think, that personal identity arises from consciousness; and consciousness is nothing but a reflected thought or perception. The present philosophy, therefore, has so far a promising aspect. But all my hopes vanish, when I come to explain the principles, that unite our successive perceptions in our thought or consciousness. I cannot discover any theory, which gives me satisfaction on this head.
In short there are two principles, which I cannot render consistent; nor is it in my power to renounce either of them, viz., [first] that all our distinct perceptions are distinct existences, and [second] that the mind never perceives any real connexion among distinct existences. Did our perceptions either inhere in something simple and individual, or did the mind perceive some real connexion among them, there wou’d be no difficulty in the case. For my part, I must plead the privilege of a sceptic, and confess, that this difficulty is too hard for my understanding. I pretend not, however,to pronounce it absolutely insuperable. Others, perhaps, or myself, upon more mature reflections, may discover some hypothesis, that will reconcile those contradictions.