Sleepers vs. Sleepless | Sanctuary | Yagaiism
The most important philosophical influence in Beggars in Spain is Yagaiism. The theory was developed by Kenzo Yagai, who also developed Y-energy. The central tenet of his theory is that all social relationships should be based on mutually beneficial contracts. Leisha struggles with this throughout the story, trying to justify giving aid to those who are "weaker" or who may seemingly have nothing economically to offer in return. She was raised in an environment where this theory was strongly accepted; her father was a wealthy support of Dr. Yagai. However, Leisha always felt a strong dedication to others regardless.
I think that Yagaiism while practical on an economic level is inhumane and doesn't take into account other variables. Not all benefits can be quantified through economics or monetary value. I am a stronger belief in charity and lending a hand to a fellow human being in need. By giving aid to someone, you may have enabled them to go on to achieve some sort of greater goal which benefits society as a whole. I disagree with Yagaiism that all relationships should necessarily need to be based on an economically mutual benefit. Everyone will be in need at some point, so generating a natural cycle of giving will benefit everyone.