Does the past matter for reasons beyond the present effects it brought about? If some alternative past had identical effects, so the present in each case would be indiscernible, would there be any philosophically relevant differences between this hypothesised "present" and the actual one?
Also, does the past retain any causal powers? (I'm guessing not, but I'd like to make sure.) Assuming determinism, must the state of the universe at time t+1 be entirely determined by the universal snapshot at time t, or is it possible that a combination of times (say t and t-1) together bring about a future state of affairs? If the former, then it would seem that the past becomes entirely irrelevant - the universe could be created ex nihilo in its present form, and the future would unfold in the exact same way. So, for all practical purposes, the past seems entirely irrelevant.
What got me thinking about all this was an issue in Artificial Life. Some have suggested that having evolved is an essential feature of 'life'. That is, to be counted as a 'living' organism, one must belong to a species that has evolved. But if this were true, then Creationism would be not merely false (which it is), but incoherent (which it surely is not). We can imagine God creating human beings in their present form. Such beings would surely still count as alive, despite not having evolved. The past just doesn't seem that crucial here. Perhaps what matters is the future. So a more plausible essential feature of life would be Ray's suggestion, i.e. that the species be "capable of open-ended evolution". (Though even that may admit of counterexamples. Imagine if God created Adam and Eve sterile. Then their species could not evolve. But I'm still inclined to describe them as being alive. Or, for a simpler example: mules!)
Could this dismissal of the past be universalised? Does it ever matter (philosophically) how the present was brought about? I'd quite like to say "no" (to the latter question, i.e. "yes" to the former), but I suspect that's a very radical position. I've heard of several "causal theories of X", for various X (though I don't know much about any of them). A consequence of my position here would be that every such theory is false (since I'm basically saying: "causes don't matter, only effects do".)
From the little I know of this stuff, a causal theory of reference / intentionality might be among the most pressing of these. The idea (if I understand it correctly) is that the meanings of representations (e.g. words, beliefs, etc.) derives, in part, from their causal history.
An example I once heard (I forget who from) is that of a "Swampman" who is miraculously created when a bolt of lightning zaps a swamp and forms an atom-for-atom replica of me. (Alternatively, just imagine God creating Adam.) Is this creature a person? Would their words (which, recall, would not be 'grounded' in past experience in any way) have any meaning?
Or imagine a pile of stones that is carefully arranged by someone to spell out a word. Those stones are then symbols, and have semantic content (i.e. meaning). But imagine if instead they had by chance been blown by the wind into those exact same positions. It seems in the latter case there is no real 'word', no meaning. It's just an appearance. But in each case the present effects are identical, the only difference is in their past causes. So, one might argue, the past clearly does matter.
That seems a quite compelling argument, but I'm still reluctant to accept it. Instead, I want to say that meaning is something we (as observers) attach to things, rather than something instrinsic to the thing itself. If I can have an intelligible discussion with the swampman, then his words have meaning (to me). If you see the windswept stone pattern and interpret it as a word, then those stones contain a meaning (to you). It makes no difference how these things were caused in actual fact; what matters is how we treat them. If we treat them as having meaning, then they (ipso facto) do have meaning (to us). That's all 'meaning' is - something we read into the world, that otherwise would not be there at all.
Does that sound at all plausible?
(I plan to read Dennett's The Intentional Stance soon, which from what I've heard might suggest a similar treatment of meaning to that which I've sketched here. I'm not sure though.)
Also, do you think there any other compelling reasons to accept the past as philosophically relevant? I'm fairly confused (but very interested!) by all this, so any feedback would be much appreciated.