16 This unique power of the heart also helps us to understand why, when we grasp a reality with our heart, we know it better and more fully. This inevitably leads us to the love of which the heart is capable, for “the inmost core of reality is love”. For Heidegger, as interpreted by one contemporary thinker, philosophy does not begin with a simple concept or certainty, but with a shock: “Thought must be provoked before it begins to work with concepts or while it works with them. Without deep emotion, thought cannot begin. The first mental image would thus be goose bumps. What first stirs one to think and question is deep emotion. Philosophy always takes place in a basic mood ( Stimmung )”. That is where the heart comes in, since it “houses the states of mind and functions as a ‘keeper of the state of mind’. The ‘heart’ listens in a non-metaphoric way to ‘the silent voice’ of being, allowing itself to be tempered and determined by it”.
Source: Dilexit Nos (Vatican.va)