You would say... inexperienced as I am, and ready to start, as the proverb says, at my own shadow, I cannot afford to give up the sure ground of principle.... and when you are further required to give an explanation of this principle, you would go on to assume a higher principle, and the best of the higher ones, until you found a resting place; but you would not refuse the principle and consequences in your reasoning like the Eristics—at least if you wanted to discover real existence.

Plato - Phaedo