Discovery is accidental, the culture trait already exists and it is by chance that we find it. Invention is altogether different. We set out to find and something and that something is found out. This is invention. Differentiating discovery and invention, Herskovits writes:
Although the casual discovery of a new food or material may lead to its use, if the foods already utilized are insufficient and there is a need for new sources of supply, a powerful spur is added to curiosity, and purposeful search is likely to ensue. Necessity is indeed often the, mother of invention and is likewise the parent of discovery as well.
With the strengthening of this factor of need we pass more and more definitely into the sphere of invention, in which the need is met not by the appropriation to use of hitherto unused thing, but by the creation of something new and fundamentally better.
Herskovits relies more on invention as the process of cultural change. The inventor is a person who invents a new machine, a new mechanical process and a new technology.
This results in a new economic system; it devises a new political scheme, or works out a new conception of the universe. The inventor in this sense is a theorist, a philosopher, a visionary, or, with less complimentary connotation, a revolutionist.
Invention has a functional role also. Ethnologists have devised the method of counting descent on one side of the family, or have developed classificatory systems of relationship terminology.
Some cultural anthropologists have explained the role of invention in the spread of culture traits. From all considerations, invention stimulates cultural change. Ogburn, in his theory of culture lag, has brought out a large number of culture traits resulting from invention of a technology.