I think you are not fro SEO that's why you asked such weird question. SEO means Search engine optimization and Google is a Search engine. So SEO is authorized by every search engine.
Google has an SEO guide for webmasters - http://googlewebmastercentral.blogspot.com/2008/11/googles-seo-starter-guide.html Need I say more?
Google does however have certain guidelines for proper SEO. So called "blackhat SEO", may get you banned. So make sure you follow guidelines.
You know it doesn't matter google exist or not. SEO reffers to all search engines: google, yahoo, bing, aol and so. Search Engine Optimisation and not Google Engine Optimisation
It's quite funny and how easy to say that 'it wont matter whether Google existed or not'. Well you can tell that to bloggers and webmasters that mainly rely on Adsense as their main income or SEO companies that really rely specifically on Google to make money, give wages to their employees and give job opportunities to people.
yes Google authorized SEo as SEO is Search engine Optimization and Google is on type of Search Engine so hoe google work without SEO..?
Yes as long as you're not trying to manipulate the rankings, lots of things that we may consider white hat link building google would frown upon.
Google Not authorizes SEO but i agree with you if SEO is not so google would not exist. Bcz PPC and online advertising all are doing SEO like as google adsense, Google Adwords etc.. more powerful search engine and website.
Simply lol. Why do you think Matt Cutts has a sub-folder in his blog called GoogleSEO? http://www.mattcutts.com/blog/type/googleseo/ Google does authorise SEO specifically SEO white hat or legitimate methods and on the other hand, Google does not authorise Black hat SEO practices so in some ways YES while some no.