Locke begins his chapter on identity and diversity by what seems to be a refusal of philosophical and theological speculation – a refusal, that is, to consider either Stoic cyclical time or theological eternity:
“When we see anything to be in any place in any instant of time, we are sure (be it what it will) that it is that very thing, and not another which at that same time exists in another place, how like and undistinguishable soever it may be in all other respects: and in this consists identity, when the ideas it is attributed to vary not at all from what they were that moment wherein we consider their former existence, and to which we compare the present. For we never finding, nor conceiving it possible, that two things of the same kind should exist in the same place at the same time, we rightly conclude, that, whatever exists anywhere at any time, excludes all of the same kind, and is there itself alone.”
Notice the drum beat of the “same”, here, doing the conceptual work – the “same kind”, the “same place”, the “same time” – as though the identity “fix” is in. Locke, in other words, is placing this discussing in a certain locale – very much sub species non-aeternitatis. The neighborhood of sameness reaches out through all time and space, but it at the same time normalizes that time and space for the purpose of identity. Locke did not make this move because he was unaware of other ideas of time and space – in fact, the chapter is full of references to those other ideas, especially those associated with the idea of the pre-existing self of the Cambridge Platonists. And at the same time, Locke is also aware of Newton. In fact, his tremendous whack at all non-respectable metaphysics is made as a sort of “clearing the ground” for the work of the true magi, of whom the most eminent was Newton. Now, Newton in his scholium had written of various senses of time – which applied to various approximations of reality:“Absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external, and by another name is called duration: relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time; such as an hour, a day, a month, a year.”
What does Newton meant by “flows equably without relation to anything external”? What after all would be this external thing? Space? Or the observer? Newton explains further that “It may be, that there is no such thing as an equable motion, whereby time may be accurately measured. All motions may be accelerated and retarded, but the flowing of absolute time is not liable to any change. The duration or perseverance of the existence of things remains the same, whether the motions are swift or slow, or none at all.”
Newtonian absolute time became an important reference in the 19th century after thermodynamics tried to capture an irreversible temporal direction in the universe - which Botzmann provided the equations for. J. Loschmidt criticized the discrepancy between Boltzmann and Newton, the latter of whom clearly allows for equations of motion that are reversible in time. “This means that if a system of hard-sphere particles starts a backward motion due to the particles reversing their direction of motion at some instant of time, it passes through all its preceding states up to the initial one, and this will increase the H-function [entropy] whose variation is originally governed by reversible equations of motion. The essential point to be made here is that the observer cannot prefer one of the situations under study, the forward motion of the system in time, in favor of the second situation, its “backward” motion.” (Alexeev, 3) Notice that this observer is an observer ex machina – for in a sense the observer, being external, cannot penetrate to absolute time, having no footing according to Newton’s scholium. And it is this that may justify Locke, who plants the observer at the very beginning of his chapter with the telling phrase, “we see”.
It is from the position of what we see that Locke wants to proceed. Thus, it is in the observer’s world that we travel, and in which, for Locke, personal identity insists. It will insist fiercely in the rumble between finite spirits and bodies, for Locke quickly throws out the relevance of our idea of God, the third substance in Locke’s system. God is equivalent to the self-evident, an absolute point of view that combines a number of piously ornamental traits (is everywhere, is eternal, etc.) that do not interfere with the real argument about identity.
That argument comes down to what sense we are to make of personal identity when we borrow the terms from our notions of bodies. Locke, beginning with the observer’s notion of the identity of the moment with itself and the place with itself, would seem to have to continue in this vein. In that sense, every passed second and every dissipated ray of light would enforce a change in identity on the living. This is an idea that Locke rejects:
“In like manner, if two or more atoms be joined together into the same mass, every one of those atoms will be the same, by the foregoing rule: and whilst they exist united together, the mass, consisting of the same atoms, must be the same mass, or the same body, let the parts be ever so differently jumbled. But if one of these atoms be taken away, or one new one added, it is no longer the same mass or the same body. In the state of living creatures, their identity depends not on a mass of the same particles, but on something else. For in them the variation of great parcels of matter alters not the identity: an oak growing from a plant to a great tree, and then lopped, is still the same oak; and a colt grown up to a horse, sometimes fat, sometimes lean, is all the while the same horse: though, in both these cases, there may be a manifest change of the parts; so that truly they are not either of them the same masses of matter, though they be truly one of them the same oak, and the other the same horse. The reason whereof is, that, in these two cases -- a mass of matter and a living body -- identity is not applied to the same thing.”
In the observer’s world, we notice that it is a question of the observer himself.
The observer has one characteristic that distinguishes it from ‘parcels of matter’ – it is alive. Plant or animal, it has a living existence. Locke’s vitalist move is even expressed in terms that will later be refined into a vitalist philosophy: unlike the watch, which receives its impetus from without, the organism receives its impetus from within. That impetus will later be the much sought after vital force of romantic science and its aftermath.