The third class of evils comprise those which everyone causes to himself by his own action. This is the largest class, and is far more numerous than the second class. It is especially of these evils that all men complain, - only few men are found that do not sin against themselves by this kind of evil. ...This class of evil originates in man's vices, such as excessive desire for eating, drinking, and love; indulgence in these things in undue measure, or in improper manner, or partaking of bad food. This course brings diseases and afflictions upon the body and soul alike.
MaimonidesThere is no difference between the pain of humans and the pain of other living beings, since the love and tenderness of the mother for the young are not produced by reasoning, but by feeling, and this faculty exists not only in humans but in most living beings.
MaimonidesDo not imagine that what we have said of the insufficiency of our understanding and of its limited extent is an assertion founded only on the Bible: for philosophers likewise assert the same, and perfectly understand it,- without having regard to any religion or opinion.
Maimonides