Saved theme in .emacs doesn't load on launch

Question

I can load the solarized-light theme when I go to customize-themes, but even though it is in my .emacs, it never loads on launch. Why is this?

(custom-set-faces
 ;; custom-set-faces was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil :underline nil :slant normal :weight normal :height 150 :width normal :foundry "apple" :family "Menlo"))))
 '(compilation-mode-line-fail ((t (:inherit compilation-error :foreground "dark cyan" :weight bold))) t)
 '(cursor ((t (:background "green1"))))
 '(rainbow-delimiters-depth-2-face ((t (:foreground "MediumOrchid1"))))
 '(rainbow-delimiters-depth-3-face ((t (:foreground "dark cyan"))))
 '(rainbow-delimiters-depth-4-face ((t (:foreground "light green"))))
 '(rainbow-delimiters-depth-5-face ((t (:foreground "HotPink1"))))
 '(rainbow-delimiters-depth-6-face ((t (:foreground "yellow1"))))
 '(slime-repl-inputed-output-face ((t (:foreground "gray100")))))

Answer 1

This worked:

(add-hook 'emacs-startup-hook
  (lambda ()
    (load-theme 'solarized-light)
    ))

Answer 2

My original answer was going to be:

Try adding (load-theme 'solarized-light t) to the top of your .emacs file.