The crossword solution for the term 'English thinker John' is 'Locke'. John Locke was an English philosopher and physician who is widely regarded as one of the most influential Enlightenment thinkers. He is known for his work in the areas of political philosophy, epistemology, and religious toleration. He is also credited with laying the foundations for modern liberal thought. His works, such as An Essay Concerning Human Understanding, Two Treatises of Government, and A Letter Concerning Toleration, are still widely read today.