One influential model of science requires that any candidate science be able to explain events by subsuming them under general laws; for example the law of universal gravitation "explains" why objects fall toward the center of the earth. But very few psychological events have ever been subsumed under reliable general laws. Moreover, some have been argued that any event that can be thus subsumed is, by the fact, not a social or psychological event at all. Thus does controversy abound even at the outset.
1. Psychology cannot be understood as a "science" because it employs scientific method. It is not at all clear that the scientific method entails.
2. Alternatively, science can be understood as a particular mode of explanation, as opposed to a particular method.
Carl Hempel's nomological- deductive ("nomos" - greek "law") model posits that an explanation is scientific if it makes reference to a universal law known to be true, and if the event being explained is an instant case of the universal law. The explanation then is simply a deduction from the universal law.
Hempel's model of science is too strong for psychology. There are no universal psychological laws known to be true. Thus Hempel offers the explanation sketch as an alternative. Although explanation sketches are not "full-fledged", they can provide good explanation where the universal from which the explanation is derived is relatively probable although not known.
Newton's Universal Law of Gravitation:
All objects attract each other with a force that's directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Under the Hempelian model, because Newtonian mechanics was replaced by relativity theory, Newtonian physics is not science at all, which is undeniably an absurd claim. Although relativity theory revealed Newton's limitations, the Newtonian model is still powerful within a specific context.
A general law is true when it has not been falsified by any previous trials. What other standard could there be? (How do you know the universal law of gravitation is true?)
In areas of psychology, such as sensory psychology, there are relatively good general laws, but these are the least interesting areas. In attempting to understand human beings, however, psychology would scarcely fit into the Hemepelian model of science.
The humanistic tradition questions whether or not psychology should me molded into a "science" at all. The humanists see the most important aspects of human psychology as precisely those unique factors which make us human.
An event is "psychological" to the extent that is result from human goals, desires, or aspirations.
The participants in psychological events are unique. Thus the event is not reducible to general laws. The ontology of psychology is not one which lends itself to scientific explanation.
The nomological-deductive model of science is not tantamount to determinism. While events are often entirely predictable, they are not necessarily determined.
Two different psychologies:
1. Scientific Psychology
- Process based
- Assumes freedom
At the end of the day psychology will not be a deterministic deductive type science, which explains even complexive features of human life.