The question asks for the psychological principle stating that all mental events have a cause and nothing in the psyche occurs randomly.
This principle is known as Psychic determinism. It posits that every mental process, whether conscious or unconscious, is determined by prior causes. Events like thoughts, feelings, memories, and actions are not accidental but are the result of preceding psychological occurrences.
Based on the definition provided in the question, Psychic determinism is the correct principle.
| List - I (Concept) | List - II (Explanation) |
|---|---|
| a. Trait | i. Specific emotional and behavioural qualities of personality that are thought to be biologically based |
| b. Type | ii. A collection of highly interconnected traits or dispositions which determine personality integration |
| c. System | iii. Clustering of many stable and enduring dispositions or qualities. |
| d. Temperament | iv. Consistent pattern of emotional and behavioural reactions a person displays across variety of situations. |