Keeping with the theme of admitting his own ignorance, Socrates regularly complains of his forgetfulness. In the "Meno", Socrates uses a geometrical example to expound Plato's view that knowledge in this latter sense is acquired by recollection. Socrates elicits a fact concerning a geometrical construction from a slave boy, who could not have otherwise known the fact (due to the slave boy's lack of education). The knowledge must be present, Socrates concludes, in an eternal, non-experiential form. In other dialogues, the "Sophist", "Statesman", "Republic", and the "Parmenides", Plato himself associates knowledge with the apprehension of unchanging Forms and their relationships to one another (which he calls "expertise" in Dialectic), including through the processes of "collection" and "division". More explicitly, Plato himself argues in the "Timaeus" that knowledge is always proportionate to the realm from which it is gained. In other words, if one derives one's account of something experientially, because the world of sense is in flux, the views therein attained will be mere opinions. And opinions are characterized by a lack of necessity and stability. On the other hand, if one derives one's account of something by way of the non-sensible forms, because these forms are unchanging, so too is the account derived from them. That apprehension of forms is required for knowledge may be taken to cohere with Plato's theory in the "Theaetetus" and "Meno". Indeed, the apprehension of Forms may be at the base of the "account" required for justification, in that it offers foundational knowledge which itself needs no account, thereby avoiding an infinite regression. Many have interpreted Plato as stating—even having been the first to write—that knowledge is justified true belief, an influential view that informed future developments in epistemology. This interpretation is partly based on a reading of the "Theaetetus" wherein Plato argues that knowledge is distinguished from mere true belief by the knower having an "account" of the object of her or his true belief. And this theory may again be seen in the "Meno", where it is suggested that true belief can be raised to the level of knowledge if it is bound with an account as to the question of "why" the object of the true belief is so. Many years later, Edmund Gettier famously demonstrated the problems of the justified true belief account of knowledge. That the modern theory of justified true belief as knowledge which Gettier addresses is equivalent to Plato's is accepted by some scholars but rejected by others.