Frege said 'a fact is a thought that is true’. Does that mean truth is factual
Frege's views about truth are complex, and there is a great deal of controversy concerning their proper interpretation. (Robert May and I have recently written a paper trying to outline Frege's views.) So I won't try to go into this in detail. But the first point to remember is that, for Frege, a "thought" is not any kind of mental episode. Frege means by a a "thought" roughly what other philosophers mean by a "proposition". So "truth is factual thoughts" would have to mean something like "truth is factual propositions", which probably sounds rather less exciting.