1-26a-קידושין-כו-א-גמירת דעת

There are two parts to a transfer of ownership 1- מעשה קנין  2-דעת  . What is the relationship between the two parts? Is the   מעשה קנין  the main component and there is a תנאי  that you need  דעת, or are they equal partners in effecting the change of ownership, or maybe the גמירת דעת  is the entire cause, and the  מעשה קנין is there to solidify his conviction of his  דעת to establish a true גמירת דעת  !?!? Enjoy!!