Saadya Gaon (882-942 AD) on his magnum opus “The Book of Doctrines and Beliefs” (Kitâb al-Amânât wal-‘I‘tiqâdât) presents a theory of the sources of knowledge, and the relation of knowledge to the commandments, prohibitions provided to humans by prophets through revelation. He thinks that reason and revelation are strengthening each other, providing thus for the faithful the necessary certainty to conduct a good life.
The following OntoUML diagram shows Saadya’s main concepts in the topic of Knowledge and Law.

Class | Description | Relations |
SourceOf Knowledge | Saadya names 4 sources of knowledge: sense perception, reason, inference and tradition. | |
Sense Perception | Sense perception is the most direct source of knowledge. E.g. I see smoke in the woods, so I know there is smoke in the woods. | is SourceOf Knowledge |
Reason | Reason is a source of knowledge in 2 ways: – can grasp truth by itself, – can infer based on sense perception. E.g. I see smoke in the woods, so using reason I infer that there is fire in the woods. | mediates between SensePerception and Inference; is SourceOfKnowledge |
Inference | Inference is source of knowledge. E.g. I know that there is fire in the woods. | is SourceOf Knowledge |
Reliable Tradition | Reliable tradition (al-kabar): “comes to a person (or a group) all at once (as opposed to being a process unfolding in time, as is the case for the other 3 modes of knowing). Furthermore, knowledge received from tradition is not only immediately received, but is additionally immediately certain to its recipient(s)” Saadya identifies tradition with the Jewish Bible, and the rabbinic writings. | is SourceOf Knowledge; is associated with Revelation |
Revelation | Revelation comes from divine sources to prophets, and is source of reliable tradition. | is associated with Tradition |
Commandment Prohibition | Commandments, prohibitions (among other texts) are parts of the Tradition. | is part of the Tradition; is Law |
LawOfReason | “The ‘laws of reason‘… are essentially characterized there as commandments and prohibitions in the Bible whose reasons could be arrived at independently by any rational human being. In other words, these are laws which ought to ‘make sense’ to any reasonable person, and, as such, are basic (one might say, natural) moral laws which, left to our own devices, we ought come up with on our own. Examples of such laws are the prohibitions against murder, adultery, theft, and lying.” The laws of reason are contained in the tradition, this way “helped by revelation”, and also the other way around: revelation is helped by reason. | is Commandment Prohibition; is associated with Reason |
LawsOf Revelation | Laws of revelation: “consists of matters regarding which reason passes no judgment in the way either of approval or disapproval so far as their essence is concerned… Saadya gives as examples of such laws: the laws demarcating Sabbath and other festival days as separate from ‘ordinary’ days, rules about who gets chosen as a prophet and/or leader, the Jewish dietary laws, certain sexual prohibitions, and laws of purity and impurity… Saadya stresses that even the most rational moral ideal is beset with vagueness about the details of how best to effect the sought after result; and so, while reason can tell us that we ought not commit adultery, it doesn’t necessarily provide us with the sorts of ‘when, where and how’ details that are needed to translate even the best moral theory into actual practice.” | is Commandment Prohibition |
Law | Commandments and Prohibitions are Laws (sharî‘a). |
Sources
- All citations from: Pessin, Sarah, “Saadya [Saadiah]”, The Stanford Encyclopedia of Philosophy (Fall 2008 Edition), Edward N. Zalta (ed.)
- Adamson, Peter, History of Philosophy without any gaps, podcast 125 – Reasoned Belief: Saadia Gaon
First published: 04/07/2019