Jack of all trades

Jack of all trades, master of none is a figure of speech, describing a person who is passably competent with many skills but is not outstandingly brilliant with any one particular skill. The term has become a cliché.

The above is actually a truncated version of the true epithet. The phrase in its entirety is "Jack of all trades, master of none, though ofttimes better than master of one". This complete phrasing of the term would seem to remove any negative connotations which follow the labeling as such in the former form.

A Jack of all trades may be a master of integration, since the individual knows enough from many learned trades and skills to be able to bring their disciplines together into a practical finished product. Such a person is known as a polymath or a Renaissance man; the prototypical example of which is probably Leonardo da Vinci.