Ultimately we're all products of our influences. Even groundbreaking business thinkers use the ideas, perspectives, and advice of others as the basis for their own thoughts and actions.

Since much of that acquired knowledge comes from books -- and since thousands of books were published this year and one can read everything -- what were the best business books in 2015?

That's a great question, one Jurgen Appelo, a speaker, author, and leader of the business network Happy Melly, set out to answer. (I published his list of the Top 50 Leadership and Management Experts last year.) His team factored in ratings, votes, and rankings in an attempt to quantify the best business books of the year.

I've included Jurgen's description of the methodology at the bottom of this post. Though truly quantifying "best" is impossible, the approach Appelo's team used makes sense, especially when you read the books that made the list.

If you see books in the list below you haven't read, check them out. All of us are products of our influences, so it only makes sense to improve both the quantity and the quality of the people we listen to.

Here we go:

The Methodology

Jurgen's team collected titles of business books throughout the year and augmented that list with books found in other "best of 2015" lists.

They then determined the earliest publication dates on Amazon and GoodReads and removed titles released before December, 1 2014, and after November 31, 2015.