Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.

The issue is that "Before Marx and Engels" takes up thousands of years. I suspect you're mostly interested in those who might have immediately preceded the two however. I would suggest restating the question one of two ways:

Who were the notable far-left thinkers, if any, in the pre-Marxist period of the 18th-19th centuries?

Something along those lines, constraining it just to the 1700s/1800s, would solve the "throughout" problem. Or if you want to target it specifically to direct influence.

What pre-Marxist far-left thinkers did Marx and Engels draw on in their own works, and what effect can be seen from it?

Either of those, or something similar, would be just fine by the rules here. Hope that helps!