FREUDIAN psychological reality begins withthe world, full of objects. Among them is a veryspecial object, the organism. The organism isspecial in that it acts to survive and reproduce,and it is guided toward those ends by its needs--hunger, thirst, the avoidance of pain, and sex.

A part--a very important part--of theorganism is the nervous system, which has as oneof its characteristics a sensitivity to theorganism's needs. At birth, that nervous systemis little more than that of any other animal, an"it" or id. The nervous system, as id, translatesthe organism's needs into motivational forcescalled, in German, Triebe, which has beentranslated as instincts or drives. Freud also calledthem wishes. This translation from need to wishis called the primary process.

弗洛伊德(Freud Sigmund 1856-1939)，奧地利精神病醫生，精神分析學派的創始人，終生從事著作和臨床治療。提齣“潛意識”、“自我”、“本我”、“超我”、“伊底帕斯情結”、“性衝動”等概念，認為人類男性天生具有伊底帕斯情結，女性天生具有厄勒剋特拉情結。其成就對哲學、心理學、美學甚至社會學、文學等都有深刻的影響，被世人譽為“精神分析之父”。他的思想極為深刻，探討問題中，往往引述曆代文學、曆史、醫學、哲學、宗教等材料。

政治學傢保爾·婁森認為，弗洛伊德“毫無疑問是曆史上最偉大的心理學傢之一”，而且是“一位偉大的思想傢”。神學傢保爾·蒂利希認為他是“所有深層心理學傢當中最有深度的一位”。