Is philosophy a science?

Philosophy is the original science.

The products of science are –supposedly– “truth and understanding”.

Does that mean that philosophy is the “first” or “main” science?

The pursuit of truth and understanding is the main purpose of philosophy. If the products of science coincides with that pursuit, then admittedly, there’s some form of connection and correlation.

correlation
ˌkɒrəˈleɪʃ(ə)n/
noun: correlation; plural noun: correlations;

a mutual relationship or connection between two or more things.
“research showed a clear correlation between recession and levels of property crime”

synonyms: connection, association, link, tie-in, tie-up, relation, relationship, interrelationship, interdependence, interconnection, interaction;

the process of establishing a relationship or connection between two or more things.

But does a correlation mean that the goals are the same?

Some would argue that science has three goals, depending on who you are:

Pure research: understanding. (researcher).

Problem-solving (applied researcher)

Dispensing solutions (practitioner / technologist)

About pure research:

Pure research is concerned with developing valid, complete, and coherent descriptions and explanations. It is interested in organizing data into the most general and parsimonious laws or qualified statements of uniformity.

About research to solve a particular problem:

Applied research is concerned with the discovery of solutions to practical problems and places its emphasis upon those factual data which have more immediate utility or application. The emphasis is on control.

About (clinical?) practitioners

Practitioners are concerned with the direct application of principles and theories from one or more fields of science. Strictly speaking, a practitioner is not a scientist, but that is not to say they are necessarily unscientific. Practitioning is like memorizing sounds of a song in a foreign language without necessarily knowing the language. It accomplishes an immediate specific end. While a practitioner may uncover a phenomenon of great importance to the understanding of nature, that is not their primary focus.

Based on the above, one could argue that pure research is philosophy and versa: philosophy is pure research.

Ergo(?) — Philosophy is pure science / Science is philosophy.