I first played PS 4 in 1997. I just recently played through it again and on this occasion wondered whether the game expressed the gamemakers own suspicion of religion, particularly with Zio, his worship of Dark Force and the attitude of his followers in the town of Kardary, then later on Rykross where Le Roof raises Chaz's ire by explaining that everything he and his party had been doing was part of the divine plan of The Great Light and now he has to complete The Great Light's plan by defeating The Profound Darkness. That climactic scene where Chaz rebels against the assumption he'll fight The Profound Darkness was something quite new and unexpected. I think basically before Chaz met with Le Roof he was happy to do whatever needed to be done to protect Algo, but Le Roof's summary of the history behind Algo and Dark Force made Chaz feel like he was a puppet in a cheap play and lost the will to fight, but then after meeting the spirits of Alis and the other heroes of PS 1 and 2 in the Elysdeon sword, he found reason to fight again. I think there is probably something intended by these parts of the story, a cautionary message advising people to think things through before putting faith in something.
Compared to PS 2, PS 4 has a more neutral attitude towards technology. The Mother Brain is not remembered as a negative influence on Algo. The Algolians are praised for recovering from the loss of the Mother Brain, learning to survive by simple means, but the technology left behind by the Mother Brain is recovered and some of it put to use again to support Algo. Overall PS 4 is very scientific and logical. Everything is explained logically. Yes obviously there is a 'magic' side to the game too, but it doesn't rely too heavily on that.

