3721. 'And this is the gate of heavens means that which serves as the ultimate degree of order, through which there is, so to speak, a way in from the natural creation. This is clear from the meaning of 'the gate' as that through which exit or entrance is made. The reason why here that which serves as the ultimate degree of order is meant is that the subject is the natural, which 'Jacob' represents. What 'a gate' means is clear from what has been stated and shown in 2871, 3187, and the fact that the natural is the ultimate degree of order from what has been introduced in 775, 2181, 2987-3002, 3020, 3147, 3167, 3483, 3489, 3513, 3570, 3576, 3671. The reason why through that ultimate degree there is so to speak a way in from the natural creation is that man's natural mind is the place through which things of heaven, that is, which are the Lord's, flow in and come down into the natural creation; and through that same mind the things that belong to the natural creation go back up, see 3702. The fact that there is so to speak an entrance from the natural creation through the natural mind into interior parts may be seen from what has been stated and shown in various places before.
[2] It seems to man as though worldly objects enter in through his physical or external senses and affect interior things, and so that there is an entrance from the ultimate degree of order into things that are within. But this is an appearance and illusion, as is evident from the general rule that what is secondary cannot flow into what is primary, or what amounts to the same, what is lower cannot flow into what is higher, or what is also the same, what is exterior into what is interior, or what is still the same, things of the world and the natural creation into those of heaven and of the spirit. For the former are grosser, the latter purer, and the grosser things that belong to the external or natural man come into being and are kept in being from those belonging to the internal or rational man. Those grosser things are unable to have any effect on the purer things but are affected by them. The nature of this influx however, seeing that appearance and illusion itself convince people that the reverse is true, will in the Lord's Divine mercy be discussed separately, where influx is the subject. This then is why it is said that through the ultimate degree of order there is, so to speak, a way in from the natural creation.