Darkness" is a state without light. "Light" is truth from the Lord, so "darkness" represents a state where truth is lacking. Here's a cogent passage from Arcana Coelestia: "The person who has yet to be regenerated is called 'a void and an empty earth', and also 'ground', in which no good or truth at all has been sown - 'void' where there is no good, and 'empty' where there is no truth. Consequently there is 'thick darkness', or stupidity and lack of knowledge about anything that has to do with faith in the Lord and so anything that has to do with spiritual and celestial life. (Arcana Coelestia 17)

1085. 'They put it on a shoulder' means that they did so with all the power they had, that is to say, they placed a good interpretation on it and excused it. This is clear from the meaning of 'shoulder' as all power. In the Word 'hand' means power, as shown already. 'Arm' means greater power still, while 'shoulder' means all power, as becomes clear also from the following places in the Word: In Ezekiel,

You push with side and with shoulder, and butt with your horns all the weak sheep till you have scattered them abroad. Ezekiel 34:21.

'With side and with shoulder' here stands for all their soul and all their power; and 'butting with horns' stands for all their strength.

[2] In the same prophet,

That all the inhabitants of Egypt may know that I am Jehovah, because they have been a staff of reed to the house of Israel. When they grasp you with the hand you will be broken, and will tear for them every shoulder. Ezekiel 29:6-7.

This refers to people who wish to probe into spiritual truths by means of facts. 'A staff of reed' stands for power of this kind, 'taking with the hand' stands for trusting in it, 'tearing every shoulder' for being deprived of all power so that they may know nothing. In Zephaniah,

That all of them may call on the name of Jehovah to serve Him with one shoulder. Zeph, 3:9.

'One shoulder' stands for doing so with one soul. and so with one power.

[3] In Zechariah,

They refused to listen, and turned a stubborn shoulder. Zechariah 7:11.

This stands for their resisting with all the power they had. In Isaiah,

They hire a smith who makes gold and silver into God. They worship, they even bow down to it. They bear it on the shoulder, they carry it. Isaiah 46:6-7.

'Shoulder' stands for their worshipping the idol with all the power they have, which is 'bearing on the shoulder'.

[4] In the same prophet,

To us a Boy is born, to us a Son is given; and the government will be upon His shoulder, and His name will be called, Wonderful, Counsellor, God, Hero, Father of Eternity, Prince of Peace. Isaiah 9:6.

This refers to the Lord, and at this point to the power He has and exercises - hence the phrase 'upon His shoulder'. In the same prophet,

I will place the key of the house of David on His shoulder, and He will open and none will shut; and He will shut and none will open.

This similarly refers to the Lord, placing on the shoulder the key of the house of David' standing for the power He has and exercises.