"You'll have more thoughts on that matter than I, my friend." This is a little wry, but entirely sincere.

Prouvaire's thoughts will very possibly be correct ones! And Enjolras is more than willing to listen to as much metaphysical speculation as Prouvaire feels like giving voice to, for as long as he likes.

But Enjolras's own thoughts on the subject of what deep truths the soul whispers to the mind can be summed up with a shrug.