The Rambam (Moreh Nevukhim 1:2) explains the consequences of Adam and Eve's eating of the forbidden fruit in a way that has always been difficult for me to understand. Here is it in Friedlander's translation:
Through the intellect man distinguishes between the true and the false. This faculty Adam possessed perfectly and completely. The right and the wrong are terms employed in the science of apparent truths (morals)... After man's disobedience, however, when he began to give way to desires which had their source in his imagination and to the gratification of his bodily appetites, as it is said," And the wife saw that the tree was good for food and delightful to the eyes" (Gen. iii. 6), he was punished by the loss of part of that intellectual faculty which he had previously possessed. He therefore transgressed a command with which he had been charged on the score of his reason; and having obtained a knowledge of the apparent truths, he was wholly absorbed in the study of what is proper and what improper...In the past, Adam was capable of distinguishing between truth and false. After eating the fruit, he was only capable of distinguishing between proper and improper. Is that such a bad change? Couldn't one argue that it is even an improvement?
R. Joseph B. Soloveitchik (Worship of the Heart, pp. 46-48) disputes this translation and suggests that rather than "the right and the wrong," the terms should preferably be translated as "the pleasant and unpleasant, the comfortable and uncomfortable, or the delightful and the ugly."
[Maimonides] set up an opposition between the cognitive-ethical truth and falsity, on the one hand, and propriety and impropriety, what is pleasing or displeasing in an aesthetic sense, on the other hand. The terms tov va-ra constitute homonyms in Hebrew, having both ethical and aesthetic connotations...In other words, prior to Adam and Eve's sin, they understood the world in terms of truth and false. Afterwards, their intellects were overpowered by aesthetic considerations. I can see that as being a tremendous fall.
The enormous joy I experienced on reading this explanation was later tempered by concern over whether this explanation is consistent with the Rambam's original Arabic. R. Yosef Kafah, in his translation of the Rambam (n. 16), implies that it cannot. However, I was wrong to impute my own ignorance of Arabic on R. Soloveitchik. I subsequently found that the Munk translation has it as "le laid et le beau" and the new Schwartz translation has it as "meguneh ve-yafeh." Marvin Fox (Interpreting Maimonides, p. 136) also translates it as "beautiful and ugly."