Water generally represents “natural truth,” or true concepts about day-to-day matters and physical things. Since all water ultimately flows into the seas, then, it follows that a sea represents a huge agglomeration of such natural truths -- usually all of the natural truth a person has, or all the natural truth a church has. Water in the sea mixes freely, and is easily stirred up by winds and currents. This is also true of the concepts we hold about natural things -- they are not all related to each other, and when relationships do exist they usually can change without damaging the concepts themselves. Many of the concepts are easily disputed, and arguments can arise like waves on the ocean -- generally with little effect other than a mixing of waters. But the sea also offers great bounty. We draw fish from it (spiritual food), float ships (doctrinal systems) on it, bathe in it (using true concepts to purify ourselves), and the water that evaporates from it and falls as rain (purer forms of truth that can attach to desires for good) makes life possible.

511. Was cast into the sea.- This signifies into the natural man, as is evident from the signification of the sea, as denoting what is scientific (scientificum) in general, which is in the natural man, consequently, the natural man as to what is scientific therein, concerning which see above (n. 270, 342). The reason of this signification of the sea, is, that water signifies truth, and truth in the natural man is called scientific; but truth in itself, is spiritual, and in the spiritual man it makes one with the affection for truth, for it is the form of the affection there. As far therefore as this affection, with its form, is thence in the scientifics which are in the natural man, so far the scientifics contain in themselves truths, and are scientific truths; for the scientifics of the natural man, considered in themselves, are not truths, but only the containing vessels of truth, wherefore scientifics are also signified by vessels in the Word.

[2] That the natural man is signified by the sea, is clear from the passages in the Word quoted above (n. 275, 342); from which it is evident that the sea, as to the water, signifies what is scientific (scientificum) in general, and the sea, considered with respect to its waves, signifies the disputation and reasoning which arise through scientifics; and because each of these is in the natural man, therefore, the sea signifies the natural man itself. But the state of the natural man is entirely according to the affection of man's love. When spiritual affection rules in man, or the affection for good and truth for the sake of good and truth, and this flows in through the spiritual man into the natural man, then the natural man is a spiritual-natural man, for he is then subordinate and subject to the spiritual man, and because they thus act as a one, both are in heaven. But when affection merely natural rules with man, then in the natural man there is not any truth, and no scientific therein is true, but dead and false. The reason is, that the scientifics there are then conjoined with affections merely natural, all of which have their origin from the loves of self and of the world; and yet real truths, being in themselves spiritual, conjoin themselves only with spiritual affections, as stated above. When truths conjoin themselves with affections merely natural, then they are no longer truths but falsities, for the affection merely natural falsifies them. Conjunctions of truth with affections merely natural, correspond to whoredoms and adulteries of various kinds, and are also meant in the spiritual sense of the Word by the varieties of whoredoms and the degrees of adulteries; there are conjunctions of the truths of the Word with the love of self and the love of the world, which correspond to these things.

[3] The signification of the sea, which denotes the natural man, and all things therein, is also from correspondence. For seas appear in various places in the spiritual world, especially about the outermost borders where the spiritual societies, or heaven itself, terminate. Seas exist there, because in the borders of heaven, and beyond them, are those who were merely natural men; they also appear there in deep places, where they have their abodes; these natural men however are not evil, for evil natural men are in the hells. The quality of those who are in those seas is evident from the seas which are seen there, but chiefly from the colour of the waters, which tend to obscurity or to clearness; if to obscurity, sensual spirits are therein, who are the lowest natural, and if to clearness, the spirits therein are interior natural. But the waters of the seas which are over the hells, are dense, black, and sometimes red; and the infernal crew therein appear like snakes and serpents, and like monsters, such as are in the seas.