Are kind acts done for selfish reasons still considered kind?

I'm not sure...but there's a reason I'm asking.

I have a rule that whenever someone asks to borrow one of my books, I just buy them their own copy. I do this because:

1. I doubt I'll ever get them back. And also because there are personal marginalia in most of them that contain my deepest secrets and I don't want anyone reading those.

2. But I also want the person to go on a journey with the book, much like I did. That's hard to do if you can't write in it, are on a time crunch to get through the book and give it back, or if you're constantly seeing passages marked up and thinking I wonder why they liked this paragraph so much?

Someone recently asked to borrow a copy of a book that has impacted greatly: Einstein: His Life and Universe by Walter Isaacson (and yes, I winced a little bit when the person asked to just bring my copy over the next time I see them lol).

Like I always do, I ordered their own copy and wrote a note in the cover. Here's what I said:

Exploring Einstein's life and universe lead me to think about the world in a whole new way. Rather than seeing it as something fixed, I realized it was malleable, changing and full of endless curiosities--and not one of them too small to wonder about.

Eisenhower said it best when he said there are few who contributed as much as Einstein did to the abundant growth in knowledge of the world in the 20th Century, yet not other who was more modest in the possession of power that is knowledge.

I think that's why this booked touched me so much, for I finally understood the great benefit of knowledge for knowledge's sake; for scratching that itch that makes you think, "I wonder how that works."

I hope your eyes are opened ever wider to the beauty of this world and the knowledge it contains, as mine were.

With love, wonder, and curiosity, Dalton.

So, is this still considered a kind act, even though the motives are half selfish and half selfless?

P.S. Einstein really was amazing. If you're curious to find out more, you can read my notes on it here.