After talking, they began drawing up plans for a book about the Young Hegelian trend of thought very popular in academic circles. Agreeing to co-author the Foreword, they divided up the other sections. Engels finished his assigned chapters before leaving Paris. Marx had the larger share of work, and he completed it by the end of November 1844. (Marx would draw from his Economic and Philosophical Manuscripts, on which he'd been working the spring and summer of 1844.)