Here I argue that Paul writes predominantly in the first person plural ("we"/"us") in the letters where he relied on information from Titus-Timothy, his co-sender. This is the 7th post in the series on the theory that Titus was Timothy.
In Philippians, Philemon, 1 Corinthians, Galatians and Romans Paul almost always uses the first person singular (I/me), even though he has co-senders in the first three of these letters. In contrast, in 1 Thessalonians the plural (we/us) is used almost exclusively. This makes perfect sense when we remember that 1 Thessalonians was written in response to information received from Timothy, one of Paul's co-senders (1 Thess 1:1; 3:6). At the time of writing Timothy knew much more than Paul about the current situation in the Thessalonian church, so it is to be expected that he had a lot of input to the composition of the letter, and this explains why it was written in the first person plural.
The plural also dominates in 2 Corinthians (Murphy-O'Connor counts 276 plurals and 228 singulars). This is explicable if Paul's co-sender, Timothy, was Titus, who had just returned to Paul from Corinth. It is very hard to explain if Timothy was not Titus.
I will now show that the instances when Paul uses the singular in 2 Corinthians can also be explained by the Titus-Timothy hypothesis.
When Paul uses the first person plural, "we", he can mean:
a) Paul and the addressees
b) Paul and his co-sender(s), e.g. Timothy.
c) Paul and his team generally.
d) Paul and those who were with him at the time referred to.
It is often difficult to know which "we" is intended. However, when he is referring to the composition of the letter we can assume that "we" means Paul and his co-sender(s). In 2 Corinthians Paul (with his co-sender, Timothy) refers to the writing of the letter using the first person plural at 2 Cor 3:1; 5:12; 5:20; 6:11; 8:1; 12:19, and perhaps at 2 Cor 1:8 and 2 Cor 6:9,
while he uses the singular at 2 Cor 6:13; 7:3; 8:3; 8:8; 8:10; 9:1; 10:1; 10:2; 10:9; 11:1; 11:16; 11:17; 11:18; 11:21; 11:23; 11:31; 12:1; 12:5; 12:11; 13:10-11.
I think there is a pattern here. Paul uses the singular whenever he is being critical of the Corinthians or being demanding of them, and he uses the plural at all other times. Thus, it is Paul alone who cajoles them into giving to the collection (2 Cor 8:3; 8:8; 8:10; 8:13; 9:1) and is critical of them 2 Cor 10:1; 10:2; 10:9; 11:1; 11:16; 11:17; 11:18; 11:21; 11:23; 11:31; 12:1; 12:5; 12:11; 13:10-11.
2 Cor 6:11-13; 7:3 are particularly interesting:
We have spoken frankly to you Corinthians; our heart is wide open to you. There is no restriction in our affections, but only in yours. In return--I speak as to children--open wide your heats also. ... Make room in your hearts for us; we have wronged no one, we have corrupted no one, we have taken advantage of no one. I do not say this to condemn you, for I said before that you are in our hearts, to die together and to live together.
The plural "We have spoken frankly" indicates that Timothy, as well as Paul, has been responsible for the preceding passages. The subsequent plurals in these verses show that Paul is here defending Timothy as well as himself. He demands that the Corinthians open their hearts to him and to Timothy. However, whereas all previous verbs of writing/speaking have been plural, here they are all singular: "I speak", "I do not say this", "I said before". This switch to the singular demands an explanation. It fits the pattern of Paul using the singular whenever he demands changes to the Corinthians' behavior.
Now, Paul's reluctance to use the plural when being critical or demanding is explicable if his co-sender, Timothy, was Titus, who was being sent back to Corinth to conduct the delicate task of organizing the collection. Titus-Timothy was (or needed to appear to be) loyal to the Corinthians. For the sake of the collection it was important that Paul not jeopardize the relationship between Titus-Timothy and the Corinthians by associating him with any hint of criticism of them. I suggest that this explains the occasions when Paul uses the singular in 2 Corinthians. I have argued here that it also explains why Paul delays his most harsh words to the subscription (2 Cor 10-13).
It is remarkable that all cases of the first person singular in 2 Corinthians fall into one of two categories:
a) cases where Paul is doubting the Corinthians or being critical of them or making demands on them (2 Cor 1:13; 2:3-10; 5:11; 6:13-7:4; 7:8; 7:12: 8:8-14; 10:1-12:16: 12:20-13:3; 13:6; 13:10).
b) cases that concern occasions when Titus was not present (2 Cor 1:15-17; 1:23-2:2; 2:12-13; 7:7; 7:9; 7:14; 7:16; 8:3; 8:23; 9:1-5; 12:17-18: 12:20-13:3; 13:10).
In conclusion, it seems to me that the strange mix of first person plural and singular in 2 Corinthians is accounted for if Paul's co-sender, Timothy, was Titus, who had just returned from Corinth and was about to return there.