と考えられる[tokangaerareru] one can think that ...
一考[ikkou] consideration
勘考[kankou] consider
考え[kangae] thinking
考えてみれば[kangaetemireba] if you think about it

考える[kangaeru] to consider
考え込む[kangaekomu] to ponder
考え事[kangaegoto] (deep) thinking
考え出す[kangaedasu] to think out
考え直して[kangaenaoshite] On second thoughts ...