#3556
Induction would be: I have looked at a data base of 4 million games and found that 1 e4 and 1 d4 offer better chances of winning.
Induction is also what AlphaZero did: I have played 700,000 games against myself and I conclude that 1 e4 and 1 d4 offer better chances of winning.
What Capablanca did was deduction.
That is the meaning of his 'theoretically' as opposed to 'in practice'
Laws of Chess -> Q, B, N are more active in the center -> it is important to secure central squares for Q, B, N
Laws of Chess -> to make a bishop exert its power a pawn must move -> e/g & d/b pawns
Laws of Chess -> king security is important -> g & b pawns not as good as e & d pawns
Laws of Chess -> e4 & d4 secure more central squares for knights than e3 & d3
altogether e4 & d4 are the best first moves.
Your post says that you do not know what deduction is. I suggest reading the wiki article to learn this.