Secular Studies Harmful

 Rabbeinu Tam (Sefer Hayashor Shaar 6): Damage from learning non-Torah wisdom:  Tenth Midah -  Wisdom which is no good. There is wisdom which destroys faith for example external wisdom, heretical wisdom and philosophy. There is no need for one who serves G d to be involved in them rather he should distance himself from them with all his strength. Because before he receives any benefit from them he will have lost his faith. It is like one who loses his possessions in the attempt to acquire other possessions and ends up having nothing. There are many who think they are wise who think this is an exalted wisdom and they think they will acquire profound and esoteric secrets – but they don’t realize they are going away from their faith. It is like a healthy person who accustoms himself to eating unhealthy foods because they taste good but he ends up destroying his health and complexion without realizing the changes. He considers himself healthy when in fact he is close to death. When a person associates with a heretic, he destroys his faith little by little without being aware. Similarly a person who studies philosophy becomes alienated from his faith little by little without being aware. While the intent and concern of philosophy is to understand the unity of G d - but when you learn it you suffer a loss. Philosophy has words and axioms which from the very beginning weaken faith. No one can be certain that when he engages in its study that he won’t lose his faith – except if he has an expert and pious teacher that will guide him and protect from the places which weaken his faith. In such a case then he will be able to avoid the pitfalls of philosophy and accomplish the goals he desires. But if he reads books of philosophy on his own or has a teacher who is not completely pious – then there is no doubt that his faith will be destroyed and he will lose more than he gains. This is the general situation that stands before all those who fear G d and therefore he has to be very careful. 

Rabbi Nachman (Sichos HaRan 103) It is better to be the fool who believes in everything’ (Mishlei 15:15). In other words, it is better to believe and have faith - even if you end up believing in stupidity and lies - if you at least also believe in the truth. This is far superior to the other extreme of being a cynical skeptic who successfully rejects stupidity and lies but at the same time also rejects the truth because of his reflexive skepticism and ridicule of all beliefs. This is what Chazal (Eduyos 5:6) say, ‘It is better that I be called a fool all my life and not be wicked for a moment before G d’.