Neither California's nor Delaware's General Corporation Law expressly prohibits directors from being represented by proxy at board meetings.   However, it appears to have been well settled in Delaware since at least 1915 that directors may not vote by proxy.  See Lippman v. Kehoe Stenograph Co. , 95 A. 895, 897 (Del. Ch. 1915).  

The California's three nonprofit corporation laws are equally explicit in prohibiting director voting by proxy:

A director shall not vote by proxy.

Cal. Corp. Code §§ 5211(c) (public benefit corporations), 7211(c) (mutual benefit corporations), and 9211(c) (religious corporations).  The omission of a similar prohibition in the General Corporation Law is puzzling.   In its silence is the legislature saying something or nothing at all?  Does the fact that director voting by proxy is not expressly prohibited by the General Corporation Law mean that it is permitted? 

Sounding The Silence

Whether expressly prohibited by statute or not, it would seem that voting by proxy would be incompatible with a director's fiduciary duty of care, which requires "reasonable inquiry".   Cal. Corp. Code § 309(a).  A director who sends a proxy will miss any information presented at the meeting, including the views of his or her fellow directors.  In addition Section 307(a)(8) provides that an "act or decision made by a majority of the directors present at a meeting . . . is the act of the board . . .".   If the director votes by proxy, presumably he or she is not present at the meeting and thus the vote of a proxy would not count in determining whether there has been an "act of the board".  It is also questionable whether a director voting by proxy could be counted for purposes of determining the existence of a quorum.