Plain version: a fact is material if it would influence the underwriter, either the decision itself or the questions the underwriter asks. It does not have to be connected to the loss that later happens.

California Insurance Code §334: materiality is determined not by the event, but solely by the probable and reasonable influence of the facts on the party to whom the communication is due, in forming its estimate of the disadvantages of the proposed contract or in making its inquiries.

Example: an owner does not mention three recent electrical fires in his building. Two months later a windstorm tears off the roof. The fires are still material, because they would likely have influenced the underwriter. The test is not whether they caused the windstorm loss.

Section 360: the materiality of a representation is determined by the same rule as the materiality of a concealment. So for silence and for statements alike, ask one question: would the fact reasonably influence the insurer? A representation may be oral as well as written.