There are two obvious purposes to writing - to benefit the reader and to benefit myself - but the choice of a blog as the medium is not an obvious one.
Consider the first purpose. If I aim to benefit readers, why would a blog be useful? There are other more official and professional avenues of presenting arguments. If I were to exclusively use these, only my most polished work would be presented, which has the benefit of conciseness and of making me look better.
The fundamental question is “what style of exposition is more valuable to the reader”. The clean, finished result? Or the whole process: motivation, intermediate steps, useless noise and failed avenues of attack - all of the sordid details? There is an analogy in the history of mathematics. Gauss and Poincaré are two influential mathematicians who had very different characters. While Gauss (in)famously presented his proofs “tabula rasa” without any motivation or intuition, Poincaré spoke extensively about his thought process and working style, and in contrast did provide motivation and intuition in his papers. Gauss’s style gives him a nice superhuman aura in its austerity, but it is not as effective at helping people understand the mathematics. The only real argument you could make for it is that it saves paper costs. I seek to emulate Poincaré - my work doesn’t need to be clean and austere - if I have something valuable to say, I’d like readers to be able to access it and gain value from it, even the messy bits.
As for myself, besides converting people to my side, I seek to improve my own writing and communication skills for the other projects in my life. Communicating ideas properly is dependent on understanding those ideas deeply enough to be able to compress and clarify them; in writing this blog, I hope to provide myself motivation to learn new things, and to identify and correct areas of my knowledge that I am not as strong in as I had thought.
Will this blog have a focus?
Right now I don’t plan to pin this blog to any particular topic. I will write as long as I am interested in the subject and as long as I think people will find it useful or at the very least amusing. If this blog ever becomes popular, I will think about splitting it up by topic to reduce the noise for people who are only interested in a subset of it. Perhaps as I develop more expertise in writing about various topics it will organically develop some sort of concrete focus.
My writing will not be self indulgent. All “meta” writing, about myself, this website, philosophy, etc. will serve some purpose. I won’t write something if I don’t think it could be valuable to other people. My writing will be sincere. I will keep the spirit of Orwell close to my heart.