405. And a third of the living creatures in the sea died. (8:9) This symbolically means that those who had lived that faith and continued to live it could not be reformed and receive life.

A third symbolizes all such, as said above. Creatures mean people who can be reformed (no. 290). The reason is that to create means, symbolically, to reform (no. 254). Their living means, symbolically, to be able by reformation to receive life. That they died means, symbolically, that people who live that faith alone cannot receive life. They cannot, because people are all reformed by a faith united to charity, thus by a faith accompanying charity, and none by faith alone; for charity is the life of faith.

[2] Since in the spiritual world the affections and consequent perceptions and thoughts of spirits and angels appear at a distance in the forms of animals or creatures on the earth called beasts, of creatures in the air called birds, and of creatures in the sea called fish, therefore the Word so often mentions beasts, birds, and fish, which nevertheless have precisely the meaning stated. So for example in the following places:

...Jehovah has a quarrel with the inhabitants of the land, for there is no truth or mercy or knowledge of God... And everyone who dwells in it will waste away along with the beast of the field and the bird of the air; even the fish of the sea will be gathered up. (Hosea 4:1, 3)

I will consume man and beast..., the bird of the heavens, the fish of the sea, ...the stumbling blocks along with the impious... (Zephaniah 1:3)

There shall be a great earthquake in the land of Israel, and the fish of the sea, the bird of the heavens, and the beast of the field... shall tremble before Me. (Ezekiel 38:18-20)

You have made Him to have dominion over the works of Your hands; You have put all things under his feet... the beasts of the fields, the bird of the air, and the fish of the sea that pass through the path of the seas. (Psalms 8:6-8)

The latter is said of the Lord.

Pray ask the beasts, and they will teach you; or the birds of the air, and they will inform you...; and the fish of the sea will tell you. Who of all these does not know that the hand of Jehovah has done this? (Job 12:7-9)

And in many other places as well.

[3] Fish, moreover, and creatures of the sea, as they are called here, mean the affections and consequent thoughts of such people as are concerned with general truths, and so who take more from a natural source than from a spiritual one. These people are meant by fish in the preceding passages, and also in the following ones:

By My rebuke I dry up the sea, I make the rivers a wilderness; their fish stink... and die of thirst. (Isaiah 50:2)

...the king of Egypt, a great whale, you who lie in the midst of your rivers, you said, "The river is mine; I made myself..".. (Therefore) I will cause the fish of your rivers to stick to your scales..., and I will leave you in the wilderness, you and all the fish of your rivers. (Ezekiel 29:3-5)

This was addressed to the king of Egypt, because Egypt symbolizes the natural level divorced from the spiritual one, and so the fish of his rivers mean people governed by doctrines, who because of them are caught up in faith separated from charity, a faith that is simply knowledge.

Because of that separation, moreover, one of the miracles in Egypt was the turning of their waters into blood, so that the fish died (Exodus 7:17-25, Psalms 105:29).

[4] Furthermore:

Why do You make mankind like fish of the sea...? Everyone draws them up with a hook, and gathers them in a net... (Habakkuk 1:14-16)

Fish here stand for people concerned with general truths and caught up in faith divorced from charity. In contrast, fish stand for people concerned with general truths and governed by a faith conjoined with charity in Ezekiel:

He said to me: "These waters flowing to the eastern boundary... enter the sea, (from which comes) every living soul that creeps... and very much fish... ...fishermen will stand by it... with a spreading of their nets. Its fish will be of the same kinds as the fish of the Great Sea, exceedingly many. (Ezekiel 47:1, 8-10)

In Matthew:

(Jesus said,) the kingdom of heaven is like a net cast into the sea, and they gathered (fish).... And they put the good ones into vessels and threw the bad away. (Matthew 13:47-49)

And in Jeremiah:

I will bring (the children of Israel) back into their land... And I will send for many fishermen...(who) shall fish them. (Jeremiah 16:15-16)

[5] Consequently, anyone who knows that fish symbolize people and things of the kind stated, can see the following: Why the Lord chose fishermen to be His disciples, and said,

Come after Me, and I will make you fishers of men. (Matthew 4:18-19)

Why the disciples, with the Lord's blessing, caught a huge multitude of fish, and the Lord said to Peter,

Do not be afraid. From now on you will catch men. (Luke 5:2-10)

Why, when they wished to exact tribute from the Lord, He told Peter to go to the sea and draw out a fish, and to give them the coin found in it for Him and for himself (Matthew 16:24-27).

Why, after His resurrection, the Lord gave His disciples fish and bread to eat (John 21:2-13).

And why He told them to "go into all the world and preach the gospel to every creature" (Mark 16:15). For the nations they were converting possessed only general truths, and were concerned more with natural things than spiritual ones.

Intellectual things -- ideas, knowledge, facts, even insight and understanding -- are more separate and free-standing than emotional things, and it's easier to imagine numbering them as individual things. Our loves and affections tend to be more amorphous -- they can certainly be powerful, but would be harder to measure. Using words like “much,” “many,” myriad” and “multitude” to describe a collection of things gives the sense that there is an exact number, even if we don't know what it is and don't want to bother trying to count. These words, then, are used in the Bible in reference to intellectual things -- our thoughts, knowledge and concepts. Words that indicate largeness without the idea of number -- “great” is a common one -- generally refer to loves, affections and the desire for good. Here's one way to think about this: Say you want to take some food to a friend who just had a baby. That's a desire for good (assuming you're doing it from genuinely good motives). To actually do it, though, takes dozens of thoughts, ideas, facts and knowledges. What does she like to eat? What do you have to cook? What do you cook well? Can you keep it hot getting to her house? Is it nutritious? Does she have any allergies? So one good desire can bring a multitude of ideas into play.