Determinism is a philosophical doctrine which derives a certain mechanism of set, uninterruptable, and causal patterns from a picture of the universe as being causally continuous. When applied to human experience it is often frustrating and frightening, because it would seem to contradict some of our most deeply cherished notions pertaining to free will and moral behavior. According to many, it threatens our nobility as sentient creatures and reduces mankind to a group of automatons who fabricate comforting notions about their ability to decide and behave on their own self-originating terms. It is highly problematic for morality since entire moral systems and ethical considerations flow from the belief that a person has the ability to choose their behaviors from amongst a group of alternatives every moment. It is for this reason that we can typically ascribe moral responsibility to a person, and all considerations of their behavior can take on a value-examining aspect only because we are originally assured of this individual autonomy that determinism would seem to challenge.
Fatalism is the absolute extreme of hard determinism, and essentially stipulates that all of human history and all things to come in the future were determined before any of it began to unfold. It is the ultimate revocation of the human ability to influence events and work toward certain outcomes over others.
The distinction between causation and constraint
Causation and constraint act against our wills and prevent us from freely acting upon our desires. Determinism is often mistakenly taken as being definitely comprised of these elements, when it in fact means no more than that the universe expresses itself in various predicatible patterns which do not necessarily chain us. These fears of severe restriction and pre-determination are more the ken of hard determinism. Causes, which, strictly speaking, are what determinism is really concerned with, do not undermine our freedom to act. Causation is simply the mechanism which drives natures self expression in repeating patterns.
Classical Compatibilism As exemplified by the statements of Hume, classical Compatibilism expresses the sentiment that true moral responsibility, be it for purposes of praise or condemnation, can only apply to a person whose motives and inclinations were accurately manifested by an action they themselves initiated from within. Things which occur for reasons beyond a persons control cannot be ascribed to that person for better or worse.