Psychology can be defined as the ‘study of mind and body’. The ancient man regarded ‘soul’ as something that was invisible and resided inside a person. He had his own explanations for the behavior of the soul and the body e.g. the soul escaped from the body when the person falls asleep. The escaped soul then performed certain actions on behalf of the person that was visible to the person who was asleep, in the form of dream.
The ancient Greek philosophers regarded three elements to be the basic ingredients of all matter including humans. There included water, air and fire respectively. They also put forward the view that contradiction is a permanent element in the world and because of it the world is influx all the time. This means that every time a phenomenon arises, there is a counter explanation to that phenomenon. One of the greatest developments of the Ancient Greek philosophers was that they put forward the view that everything consists of small indivisible particles and these particles act upon the soul to create sensations. This was later found to be true with the discovery of atoms. Amongst the notable Ancient Greek thinkers/philosophers is Aristotle,who is considered to be one of the greatest thinkers/philosophers in the history of mankind. According to Aristotle, man is a biological being whose functions include eating, perceiving, having children, thinking and doing things. Aristotle was of the view that ideas in the human beings tend to become associated with each other and there are three reasons for the association of ideas which he gave;
1. Similarity: It means that the mind tends to see the certain similar patterns between two things and relates them together. This is the simplest explanation of the association of ideas where two events which a person witnesses have certain common elements.
2. Contiguity: This refers to two things or events happening close to each other so that the person is able to relate them to each other.
3. Contrast: It means that two events or ideas are completely opposing to each other, which results in the formation of a link between the two. Humans tend to associate the ideas together.
During this long history down to the middle of the 19th century, psychology was cultivated by able thinkers who did not realize their need of carefully observed facts and relied on information derived from the past experiences. And today psychology is nurturing every stream of life where it studies the human activities, in relation to its environment.