Plato's Phaedo - a syntax question

Question

Plato, Phaedo, 105b-c:

εἰ γὰρ ἔροιό με ᾧ ἂν τί ἐν τῷ σώματι ἐγγένηται θερμὸν ἔσται, οὐ τὴν [105ξ] ἀσφαλῆ σοι ἐρῶ ἀπόκρισιν ἐκείνην τὴν ἀμαθῆ, ὅτι ᾧ ἂν θερμότης

I guess it can be rearranged so:

εἰ γὰρ ἔροιό με : " τί ἐν τῷ σώματι ἐγγένηται ᾧ ἂν θερμὸν ἔσται ", οὐ τὴν [105ξ] ἀσφαλῆ σοι ἐρῶ ἀπόκρισιν ἐκείνην τὴν ἀμαθῆ, ὅτι ᾧ ἂν θερμότης

My translation:

If you should ask me "What comes to be in the body by which it [i.e. the body] will be hot?", I won't give you that safe, ignorant answer, that [it is] hotness by means of which [the body will be hot].

But I can't understand some problems:

(1) According to The Cambridge Grammar of Classical Greek, 2019, p. 499, we have this structure with ἂν:

(subordinate clause) subjunctive + ἂν / (main clause) future indicative, etc.

But to my knowledge, here we have an inverse structure in the (in?)direct question:

τί ἐν τῷ σώματι ἐγγένηται (aor subj) ᾧ ἂν θερμὸν ἔσται (fut ind)

(2) I think that the conditional structure here is as follows:

εἰ γὰρ ἔροιό (opt) ... ἐρῶ (fut ind ?)

I can't find the same conditional structure in grammar books.

Answer 1

The syntax of the subordinate question is actually different from your rearrangement, in a way that can be hard to grasp for speakers of languages (like English) that lack that particular syntax.

It might be easiest to understand if we start from the answer rather than the question. The answer proposed (or rejected) by Socrates is ᾧ ἂν θερμότης, which is elliptical and can be expanded to the following:

ᾧ ἂν θερμότης ἐν τῷ σώματι ἐγγένηται θερμὸν ἔσται.
"That for which heat arises in the body will be hot."

Given that the answer is "heat", how can we phrase the question? Greek does it simply like this:

ᾧ ἂν τί ἐν τῷ σώματι ἐγγένηται θερμὸν ἔσται;
"That for which what arises in the body will be hot?"

That English translation, however, is almost incomprehensible because English doesn't allow forming interrogatives within a relative clause. So you have to rephrase it more wordily, along the lines of:

"What is X, such that when X arises in the body for something, that thing will be hot?"

This also explains the ἄν, which is part of the relative clause and goes with the subjunctive ἐγγένηται rather than the indicative ἔσται.

On your second question, you're right -- this is a mixed conditional with optative in the protasis and future indicative in the apodosis. There is a brief discussion of this in Smyth 2359.