The written content of the website is published under the CC BY 4.0 license. Basically, the text is only very loosely copyrighted. Feel free to quote it (even fairly hearty portions), you don't need to ask for my permission. Just remember to credit Thoughtful Inquiry and link back to the page where you found it.
You can find the source code on Github under the MIT license.
The visual assets and design, however, fall under a more stringent copyleft non-commercial CC BY-NC-SA 4.0 license. I can't really think of a valid reason to repurpose what is essentially branding for this specific website.
I'm not a big fan of copyright, or the broader concept of intellectual "property", in general. In my view, it mostly tends to stifle rather than protect creativity and stems in large part from a misguided and futile compulsion for control. I see it as an imperfect workaround for a symptom, rather than the core issue. Namely, the current priorities of most of our societies, which champion profits over basically anything else. If creators' survival didn't depend as drastically on monetization, they'd probably mellow on the urge to micromanage what others do with their ideas once they've put them out there.
There's a good chance I'll just pass all the website's writing into the public domain (i.e. no copyright at all) once I've gained some following.As it stands, I'm mostly using the BY clause in the hope of building some backlinks and traction in the beginning.
People tend to conflate credit, plagiarism, and copyright into a single concept. I can simultaneously think that crediting the original author(s) is important and plagiarism is lame, yet dislike copyright.
To only take music as an example, I think the world would be a worse place without remixes, samples, covers, or mashups. Overall, I'm most likely fine with whatever derivative of my work you come up with if it's motivated by a desire to improve upon the source material, create something new with it or just have fun.
If you think your specific use case legitimately warrants a loosening of the above-mentioned licenses, or you're generally unsure of where it falls, you can always ask me.
