What are the defining features of Capitalism? What are the necessary and sufficient conditions for an economic system (or mode of production) to be classified as "Capitalism"?

Is it markets? Is it for-profit corporations? Is it limited liability companies? Is it workers selling their labour to capitalists/employees? Is it freedom to set up companies? Is it a low degree of government productive activity? Is it a subset of these or other elements? 

I imagine the answer would depend on a particular schools of thought, so in principle I would expect different answers.

Disclaimer 1: this question is not requesting opinions about what capitalism is, it is not, it should be, it should be not, but authoritative answers, with proper references.

Disclaimer 2: for those voting to close this as too-broad, I asked on meta whether this question was on-topic, and (albeit not a popular post) it seems people agreed it was.
In this article, sociologist Erik Olin Wright provides a definition of 
capitalism (from a socialist tradition):


  Many people equate capitalism with the idea of a market economy. Capitalism is not simply an economy in which markets play a central role in 
  coordinating economic activity; it is a specific kind of  market  economy,  one  in  which  workers  do  not own and control the firms in which they work, capital  is  privately  owned  and  allocated  to  alternative purposes  on  the  basis  of  private  economic  returns  (or, equivalently, on the basis of private profit-making),  and  labor  is  allocated  to  economic  activities through labor markets.