The Western hammer

Therefore, on account of this new expression (filioque), which is only your own opinion, you have charged the Savior which three calumnies: you have said what He did not say, made Him say what He did not say, and taught an idea that does not even follow from His words, but which, on the contrary, His teaching denies; and fourthly, you introduce dogmas in rivalry with Him. What shall we take first? On the one hand, He Himself said, ‘He will receive from that which is mine’ but not ‘from me’; then, on the other hand, you rely on Him to teach the very thing that the phrase ‘from me’ means, implying that He indeed taught it. So, on the one hand, as you indeed prescribe, you murder the persons by hammering them together – indeed, something which He never affirmed. He taught the disciples by means of His words, declaring His mind, which is not at all knowable through the immaculate dialectic of processions. And He taught us that the concrete, personal procession of the Spirit is from the Father, so that if, as you say, the Spirit proceeds from the Son as well as from the first Person, at least make your theology applicable to all the persons, so as not to slight the Lord. But the Lord Himself did just this by means of the second phrase. He who finds in the grace of theology nothing reliable or consistent will soon discover that grace is insane.

St. Photios